A method includes receiving, by a level two (L2) controller, a first request for a cache line in a shared cache coherence state; mapping, by the L2 controller, the first request to a second request for a cache line in an exclusive cache coherence state; and responding, by the L2 controller, to the second request.

A method includes receiving, by a level two (L2) controller, a write request for an address that is not allocated as a cache line in a L2 cache. The write request specifies write data. The method also includes generating, by the L2 controller, a read request for the address; reserving, by the L2 controller, an entry in a register file for read data returned in response to the read request; updating, by the L2 controller, a data field of the entry with the write data; updating, by the L2 controller, an enable field of the entry associated with the write data; and receiving, by the L2 controller, the read data and merging the read data into the data field of the entry.

A device includes a data path, a first interface connected to the data path and configured to receive a request from a processor package to write a data value to a memory address, and a controller connected to the data path and configured to receive the request to write the data value to the memory address and to calculate a Hamming code of the data value. The controller is configured to transmit the data value and the Hamming code on the data path. The device includes an external memory interleave connected to the data path. The external memory interleave is configured to receive the data value and calculate a test Hamming code of the data value and to determine whether to send the data value to an external memory interface to be written to the memory address based on a comparison of the Hamming code and the test Hamming code.

A device includes an interconnect and a plurality of devices connected to the interconnect. The plurality of devices includes a first interface connected to the interconnect and a second interface connected to the interconnect. The plurality of devices further includes a first memory bank connected to the interconnect and a second memory bank connected to the interconnect. The plurality of devices further includes an external memory interface connected to the interconnect and a controller configured to establish virtual channels among the plurality of devices connected to the interconnect.

A device includes a memory bank. The memory bank includes data portions of a first way group. The data portions of the first way group include a data portion of a first way of the first way group and a data portion of a second way of the first way group. The memory bank further includes data portions of a second way group. The device further includes a configuration register and a controller configured to individually allocate, based on one or more settings in the configuration register, the first way and the second way to one of an addressable memory space and a data cache.

A method includes determining, by a level one (L1) controller, to change a size of a L1 main cache; servicing, by the L1 controller, pending read requests and pending write requests from a central processing unit (CPU) core; stalling, by the L1 controller, new read requests and new write requests from the CPU core; writing back and invalidating, by the L1 controller, the L1 main cache. The method also includes receiving, by a level two (L2) controller, an indication that the L1 main cache has been invalidated and, in response, flushing a pipeline of the L2 controller; in response to the pipeline being flushed, stalling, by the L2 controller, requests received from any master; reinitializing, by the L2 controller, a shadow L1 main cache. Reinitializing includes clearing previous contents of the shadow L1 main cache and changing the size of the shadow L1 main cache.

An apparatus includes a CPU core and a L1 cache subsystem including a L1 main cache, a L1 victim cache, and a L1 controller. The apparatus includes a L2 cache subsystem coupled to the L1 cache subsystem by a transaction bus and a tag update bus. The L2 cache subsystem includes a L2 main cache, a shadow L1 main cache, a shadow L1 victim cache, and a L2 controller. The L2 controller receives a message from the L1 controller over the tag update bus, including a valid signal, an address, and a coherence state. In response to the valid signal being asserted, the L2 controller identifies an entry in the shadow L1 main cache or the shadow L1 victim cache having an address corresponding to the address of the message and updates a coherence state of the identified entry to be the coherence state of the message.

A method includes receiving, by a L2 controller, a request to perform a global operation on a L2 cache and preventing new blocking transactions from entering a pipeline coupled to the L2 cache while permitting new non-blocking transactions to enter the pipeline. Blocking transactions include read transactions and non-victim write transactions. Non-blocking transactions include response transactions, snoop transactions, and victim transactions. The method further includes, in response to an indication that the pipeline does not contain any pending blocking transactions, preventing new snoop transactions from entering the pipeline while permitting new response transactions and victim transactions to enter the pipeline; in response to an indication that the pipeline does not contain any pending snoop transactions, preventing, all new transactions from entering the pipeline; and, in response to an indication that the pipeline does not contain any pending transactions, performing the global operation on the L2 cache.

A data processing system comprises a requesting node; a home node to control coherency amongst data stored by the data processing system; and one or more further nodes, at least one of the further nodes having a memory; the requesting node being configured to issue a data handling transaction to the home node, the data handling transaction defining a data handling operation relating to a range of memory addresses, the requesting node being configured to maintain an address hazard at the requesting node inhibiting issue of another data handling transaction for that range of memory addresses until the requesting node is notified by the home node that the data handling transaction has completed; the home node being configured, in response to the data handling transaction, to issue one or more data handling instructions to cause one or more given nodes of the one or more further nodes to perform the data handling operation, the home node being configured to notify completion to the requesting node in response to the issue of the one or more data handling instructions to the one or more given nodes.

In an embodiment, a system may include an interconnect device comprising first, second, and third ports; a first processor coupled to the first port; a second processor coupled to the second port; and a system memory coupled to the third port. The interconnect device may be to: receive, from the first processor via the first port, a speculative read request for a data element stored in the system memory, where coherence of the data element is managed by the second processor, receive a direct read request for the data element, merge the direct read request with the speculative read request, and transmit the data element directly to the first processor via the first port. Other embodiments are described and claimed.